Auditory Cortex Characteristics in Schizophrenia: Associations With Auditory Hallucinations

Abstract

There were no significant differences between AH+ and AH− patients in cortical thickness in the PT or STG, or in auditory cortex surface area in any of the regions investigated. Group differences in cortical thickness in the left HG was not affected by duration of illness or current antipsychotic medication. Conclusions: AH in schizophrenia patients were related to thinner cortex, but not smaller surface area of the left HG, a region which includes the primary auditory cortex. The results support that structural abnormalities of the auditory cortex underlie AH in schizophrenia.

Meta-analytic evidence for the plurality of mechanisms in transdiagnostic structural MRI studies of hallucination status

“…Overall, findings were heterogeneous, with few direct replications. In schizophrenia, the most consistent findings were reductions in CT in the left or right temporal gyrus for patients with hallucinations compared to those without 75,76,94 , coincident with the reductions in GM in left MTG observed in the meta-analysis ( Figure 3). However, two studies reported increases in GM in temporal regions with hallucinations 88,90 .…”

“…28 studies employed a regional and/or non-voxelwise approach to evaluate structural MRI data with respect to hallucination status: seven studies performed VBM restricted to predefined ROIs 43,61,69-73 , one performed sourcebased morphometry 74 , nine explored cortical thickness (CT) and/or surface area [75][76][77][78][79][80][81][82][83] , three investigated gyral/sulcal properties 43,84,85 , and 11 assessed structure-specific shape parameters 43,81,83,[86][87][88][89][90][91][92][93] . Results are summarized in Tables 5-6.…”

Cortical thickness abnormalities in bipolar disorder patients with a lifetime history of auditory hallucinations

“…The finding of thicker , rather than thinner cortex in the HG in BD+ patients was somewhat contrary to our hypothesis. We have in a previous study shown that schizophrenia patients with a lifetime history of auditory hallucinations had thinner cortex in the left HG compared to schizophrenia patients without a lifetime experience of auditory hallucinations . In schizophrenia, post mortem studies have shown alterations in layer III of the auditory cortex, including reduced pyramidal somal size, less dendritic arborisation and fewer axon terminals .…”

“…We have in a previous study shown that schizophrenia patients with a lifetime history of auditory hallucinations had thinner cortex in the left HG compared to schizophrenia patients without a lifetime experience of auditory hallucinations. 48 In schizophrenia, post mortem studies have shown alterations in layer III of the auditory cortex, including reduced pyramidal somal size, less dendritic arborisation and fewer axon terminals. [49][50][51] Such findings could be consistent with thinner cortex and smaller volumes of the auditory cortex typically found in schizophrenia patients with auditory hallucinations.…”

“…20,21 We previously investigated the thickness and surface area of the auditory cortex in schizophrenia spectrum patients (n = 194), and found that a lifetime history of auditory hallucinations was associated with thinner cortex in the left HG compared to those without a lifetime history of auditory hallucinations. 22 Whether there is an overlap in pathophysiology and aetiology between severe mental disorders such as BD and schizophrenia remains a matter of intense investigation. The existence of such an overlap has been supported by evidence suggesting commonalities in genetic risk 23,24 and brain structural abnormalities.…”